// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_FTP_FTP_CTRL_RESPONSE_BUFFER_H_
#define NET_FTP_FTP_CTRL_RESPONSE_BUFFER_H_

#include <queue>
#include <string>
#include <vector>

#include "base/macros.h"
#include "net/base/net_export.h"
#include "net/log/net_log.h"

namespace net {

struct NET_EXPORT_PRIVATE FtpCtrlResponse {
    static const int kInvalidStatusCode;

    FtpCtrlResponse();
    FtpCtrlResponse(const FtpCtrlResponse& other);
    ~FtpCtrlResponse();

    int status_code; // Three-digit status code.
    std::vector<std::string> lines; // Response lines, without CRLFs.
};

class NET_EXPORT_PRIVATE FtpCtrlResponseBuffer {
public:
    FtpCtrlResponseBuffer(const BoundNetLog& net_log);
    ~FtpCtrlResponseBuffer();

    // Called when data is received from the control socket. Returns error code.
    int ConsumeData(const char* data, int data_length);

    bool ResponseAvailable() const
    {
        return !responses_.empty();
    }

    // Returns the next response. It is an error to call this function
    // unless ResponseAvailable returns true.
    FtpCtrlResponse PopResponse();

private:
    struct ParsedLine {
        ParsedLine();
        ParsedLine(const ParsedLine& other);

        // Indicates that this line begins with a valid 3-digit status code.
        bool has_status_code;

        // Indicates that this line has the dash (-) after the code, which
        // means a multiline response.
        bool is_multiline;

        // Indicates that this line could be parsed as a complete and valid
        // response line, without taking into account preceding lines (which
        // may change its meaning into a continuation of the previous line).
        bool is_complete;

        // Part of response parsed as status code.
        int status_code;

        // Part of response parsed as status text.
        std::string status_text;

        // Text before parsing, without terminating CRLF.
        std::string raw_text;
    };

    static ParsedLine ParseLine(const std::string& line);

    void ExtractFullLinesFromBuffer();

    // We keep not-yet-parsed data in a string buffer.
    std::string buffer_;

    std::queue<ParsedLine> lines_;

    // True if we are in the middle of parsing a multi-line response.
    bool multiline_;

    // When parsing a multiline response, we don't know beforehand if a line
    // will have a continuation. So always store last line of multiline response
    // so we can append the continuation to it.
    std::string line_buf_;

    // Keep the response data while we add all lines to it.
    FtpCtrlResponse response_buf_;

    // As we read full responses (possibly multiline), we add them to the queue.
    std::queue<FtpCtrlResponse> responses_;

    BoundNetLog net_log_;

    DISALLOW_COPY_AND_ASSIGN(FtpCtrlResponseBuffer);
};

} // namespace net

#endif // NET_FTP_FTP_CTRL_RESPONSE_BUFFER_H_
